Pediatric bed

ABSTRACT

A bed platform is suspended within a support frame having transparent and removable plastic end walls and plastic mesh sides slidable on a Tambour track between raised and lowered positions. As the sides are raised, they slope inwardly over and above the platform to discourage climbing. The support frame is mounted on a caster supported base having upstanding end posts attached to the frame and adjustable height-wise by a motor driven lift. The platform is supported on the ends of the frame and is adjustable for Trendelenburg and reversed Trendelenburg positioning. Affixed to the platform is a mattress frame which includes adjustable and pivotal portions for Gatch positioning. The mattress is molded with a shell-like configuration to fit over the mattress and support frame and includes living hinges to permit folding into various Gatch positions. It also includes grippers along its underside for positive grip sheet placement.

United States Patent [191 Propst 5] Dec. 25, 1973 PEDIATRIC BED Robert L. Propst, Ann Arbor, Mich.

[73] Assignee: Herman Miller, Inc., Zeeland, Mich.

[22] Filed: Sept. 27, I972 [21] Appl. No.: 292,808

Related US. Application Data [62] Division of Ser. No. 175,505, Aug. 27. 1971.

[75] Inventor:

[52] US. Cl 5/345, 5/91, 5/97, 5/200, 5/352 [51] Int. Cl. A47c 27/08 [58] Field of Search 5/91, 200, 320, 345, 5/351, 352, 353.1, 357; 24/90 C, 113 R, 243

Primary ExamineP-Casmir A. Nunberg Attorney-Daniel Van Dyke [57] ABSTRACT A bed platform is suspended within a support frame having transparent and removable plastic end walls and plastic mesh sides slidable on a Tambour track between raised and lowered positions. As the sides are raised, they slope inwardly over and above the platform to discourage climbing. The support frame is mounted on a caster supported base having upstanding end posts attached to the frame and adjustable height-wise by a motor driven lift. The platform is supported on the ends of the frame and is adjustable for Trendelenburg and reversed Trendelenburg positioning. Affixed to the platform is a mattress frame which includes adjustable and pivotal portions for Gatch positioning. The mattress is molded with a shell-like configuration to fit over the mattress and support frame and includes living hinges to permit folding into various Gatch positions. It also includes grippers along its underside for positive grip sheet placement.

8 Claims, 36 Drawing Figures mnmsonmz lm 3,780,387

sum ear 9 PEDIATRIC BED CROSS-REFERENCE TO RELATED APPLICATION This is a division, of application Ser. No. 175,505 filed Aug. 27, 1971.

BACKGROUND OF INVENTION This invention pertains to a pediatric bed, and more particularly to an improved versatile bed for use in child care centers such as hospitals.

Hospital beds or cribs for children have undergone little or no change over the years and indeed, applicant is unaware of any prior art on the market today which is versatile enough to be utilized properly as a crib or youth bed. Basically, the type of structure present today for young children is the traditional stainless steel or chrome plated cage called a crib. This in and of itself is one major disadvantage of present bed construction since a young patient admitted to the hospital is frequently quite frightened. Placing him in a cage type crib does little to reassure him or calm his fears. With regards to beds available for slightly larger children wherein a crib is unfeasible, present proposals call for a bed very similar to that used for adults simply modified slightly as to its size. One important overall disadvantage then is the lack of a bed which will accommodate both infants and youths. As a result, a pediatric department is faced with either buying a crib, a youth bed, or both in order to meet its needs. With the advant of over-crowded hospitals and the associated demand on floor space within hospitals, this is a luxury which can be ill afforded. Since the need is never completely constant within a pediatric department, the requirement of two different types of beds or cribs not only greatly increases the overall cost factor, but puts a demand on storage space or in the alternative the nonutilization of floor space. Thus, there is an extreme need today for a pediatric bed which is serviceable as a crib for the tiniest infant to a bed which is likewise serviceable for an older youth.

Another significant disadvantage of the prior art today is the lack of versatile adjustment as to height and positioning. While it is old to provide a bed having sides adjustable with regards to height, they are generally difficult to handle, and tend to jam when being raised or lowered. Also, the latching mechanism is many times within the reach of the patient, a potentially dangerous situation especially in regards to children. A second disadvantage of present proposals in this regard is the difficulties encountered in height adjustment. A bed which is utilized for both a tiny infant and an older child must be adjustable height-wise within a wide range. Applicant is unaware of any prior art child s bed that can be quickly and efficiently raised or lowered from the floor to an adult height electri' cally. Other important positionable adjustments include Trendelenburg positioning and Gatch positioning. Applicant is unaware of any pediatric bed which combines all of these adjustments in a simple to operate and economical fashion. Although it is old to provide a bed having one or more of these types of adjustments possible, additional disadvantages with these types of beds is their inability to be adjusted longitudinally to adapt to various sized individuals. The growth rate of an individual is a maxiumum in his younger years and thus, a childs bed adjustable for Gatch positioning, should also be adjustable so that the Gatch positioning can be varied to accommodate a child having various sized backs, legs and central body portions. That is, the distance in children from the foot to the knee; the knee to the waist; and the waist to the head can vary greatly. Applicant is unaware of any child's bed which provides in addition to Gatch positioning, an adjustment for the various dimensions described. Thus, there is a need today for a pediatric crib which can be quickly and easily adjusted with respect to height, Trendelenburg positioning and Gatch positioning.

Yet another major disadvantage in existing proposals is that they are generally comprised of bars or *tubes which have various drawbacks. To begin with, they affect the overall visibility into and out of the bed. This is distracting to the child as well as the nurse tending the child since they cannot always ascertain the exact status of the child in the bed from their various work positions in and around the bed. Also, bars and tubes present a difiicult and time consuming cleaning problem. Furthermore, if the pediatric bed is to be utilized for small infants, there must be some assurance that the infant cannot extricate himself from within the confines of the bed and possibly injure himself in the fall. Thus, there is a need for a pediatric crib or bed which can be conveniently and yet positively enclosed to prevent a child from climbing out under normal circumstances. On the other hand, the bed must be adaptable to apply or attach orthopedic appliances or portable support environments such as oxygen tents thereto. Other orthepedic appliances such as traction equipment generally requires projections of the equipment past the extremities of the bed. Applicant is unaware of any pediatric bed which has easy to remove end walls which when being used are transparent to permit clear vision into the bed. Other disadvantages with present beds constructed of bars and tubular elements is their tendency to injure the child when he becomes frustrated or during excessive play strikes his head or hand against the tube elements. Applicant is unaware of a prior art bed having yieldable mesh siding which permits clear vision therethrough but prevents injury under normal circumstances and use.

Yet other drawbacks lie in the mattress pans and mattresses which are generally heavy and difficult to raise when it is desired to place the patient in a sitting position. In fact the weight along of existing proposals make them difficult and clumsy for a nurse to move around. Finally, even though applicant is unaware of any present proposal which has any significant versatility to meet present day demands, those that do attempt to provide some versatility do so at very high costs. Since hospitals are in an era of spiraling costs, this is no small consideration.

Thus, there is a need today for a pediatric bed which has extreme versatility in both its utilization and adjustability while at the same time presenting an attractive looking unit at a cost that is not prohibitive.

SUMMARY OF INVENTION In accordance with this invention, a novel and versatile pediatric bed is comprised of a platform means having a mattress affixed thereto, the platform means is suspended by a support frame which includes a pair of end walls and adjustable sides. The support frame is suspended from a caster mounted base and is adjustable height-wise by a lift mechanism.

In preferred aspects, the side and end walls are transparent to permit clear peripheral vision into and out of the bed with the end walls being removable to facilitate the attachment of external orthopedic equipment. The side walls preferably slant inwardly when in their extreme upper position to discourage and inhibit an infant from climbing out of the bed when it is utilized as a crib. In other preferred aspects, the platform is adjustable for Trendelenburg positioning while the mattress is affixed to an auxiliary frame mounted on the platform which is adjustable for Gatch positioning. All components are comprised of aluminum or plastic to minimize its weight and make it easy to clean.

A principal advantage of this invention is its complete versatility for utilization as a crib, playpen or youth bed at varying heights.

Additional advantages provided by this invention is the versatility provided by this bed which provides Trendelenburg and Gatch positioning while at the same time providing an attractive overall appealing package of relatively light-weight and low cost. The package is attractive both in appearance for the sake of the user as well as its overall durability.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the pediatric bed provided by this invention;

FIG. 2 is a fragmentary view of portions of the bed shown in FIG. 1 shown in an exploded perspective;

FIG. 3 is a perspective view of one of the Trendelenburg plates utilized in FIG. 1;

FIG. 3A is a cross sectional view taken along line 3A-3A in FIG. 3;

FIG. 3B is a perspective view of the end panel provided by this invention;

FIG. 4 is a side view of the handle assembly utilized in connection with the Trendelenburg plate shown in FIG. 3;

FIG. 5 is an elevation view shown in cross section of the platform height adjustment mechanism provided by this invention;

FIG. 6 is a fragmentary view of the sides and latch mechanism provided by this invention;

FIG. 6A is a cross sectional view taken along line 6-6A in FIG. 6;

FIG. 7 is an elevation view of one of the telescoping latch tubes shown in FIG. 6;

FIG. 8 is an elevation view of another of the telescoping latch tubes shown in FIG. 6;

FIG. 9 is a perspective view of the mattress provided by this invention;

FIG. 10 is an exploded perspective view of the mattress frame and platform provided by this invention;

FIG. 11 is a plan view of the mattress frame shown in FIG. 10;

FIG. 12 is a side elevation view of the frame shown in FIG. 11;

FIG. 13 is an end view of the frame shown in FIGS. 11 and 12;

FIG. 14 is a perspective view of the bottom of the mattress shown in FIG. 9;

FIG. 15 is a side view partially cutaway to illustrate the mattress shown in FIG. 14 in a Gatch position;

FIG. 16 is a bottom view of the mattress shown in FIG. 14;

FIG. 17 is. a cross sectional view taken along line l7l7 of FIG. 16;

FIG. 18 is a sectional view taken along line 1818 of FIG. FIG. 19 is a 19ll9 of FIG. FIG. 20 is a 2020 of FIG. FIG. 21 is a 2l-2ll of FIG. FIG. 22 is a 2222 of FIG.

FIG. 23 is a cross 23-23 of FIG. 16;

FIGS. 24-31 are perspective views of the bed provided by this invention illustrating the bed and sides in a variety of adjusted height, Trendelenburg and Gatch positioning;

FIG. 32 is an elevation view in cross section of an alternative mattress frame and platform construction; and

FIG. 33 is a perspective view similar to FIG. 1 of an alternative bed arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring briefly to FIGS. 1 and 10 of the drawings the bed 10 provided by this invention includes a mobile base 11 mounted on casters 12. Each end of the base includes an end post 13 from which is suspended a support frame 14 having a pair of sides 15 and end panels 16. A mattress 17 is mounted on a mattress frame 18 (Fig. 10) which is anchored to a mattress platform 19. Platform 19 is in turn suspended from support frame 14. Frame 18 is movable to various Gatch positions (one of which is shown inFIG. 1) while platform 19 is mounted to frame 13 through a plurality of Trendelenburg plates 20 to permit the platform to be oriented in Trendelenburg or reverse Trendelenburg positioning. Gatch positioning relates to the knees-up, back-up positioning while Trendelenburg positioning relates to the overall slope of the mattress relative the horizontal. End panels 16 are removable to permit the utilization of traction or other orthopedic attachments while the upper portion of sides 15 are sloped inwardly when in a full up position to inhibit a child from climbing out.

Referring now in greater detail to FIGS. 1 and 2, mobile base 11 is shown comprised of a generally longitudinally extending channel or frame element 21 which extends the overall longitudinal length of the bed. A pair of horizontal legs 22 extend laterally out in opposite directions from channel 21 near each end and are anchored at their outer end to a caster 12. This construction provides a low profile base having a generally rectangular configuration with a caster at each corner to provide excellent stability for the bed. Casters 12 are journaled in an individual housing 23 in a conventional fashion and preferably include some type of manually releasable brake means (not shown) so that the bed can be positioned in a desired location and prevented from unintentional movement.

Extending generally vertically upwards from each end of channel member 21 is an end post 13 preferably having a tubular configuration. End posts 13 are adapted to telescope within corresponding portions of the support frame 14 from base 11. An elbow 24 (FIG. 5) interconnects each post 13 with the end of channel 21. Elbow 24 accommodates part of the lift mechanism which will be described in more detail hereinafter.

cross cross 16;

cross 16;

cross 1 6;

cross 1 6;

sectional view taken along line sectional view taken along line sectional view taken along line sectional view taken along line sectional view taken along line Continuing in detail with reference to FIGS. 1 and 2, support frame 14 includes a pair of identical end frames 26, 26 which are ridigly interconnected by a pair of longitudinally extending cross bars 27 and 28 spaced laterally from each other and welded or affixed in some other fashion to the underside of end frame 26, 26. Each end frame 26 includes a central vertical post 29 which telescopes over end posts 13 for support of frame 14 by base 11. The telescoping association between end posts 13 and frame posts 29 adds to the overall rigidity and stability of interconnected end frames 26.

Each end frame 26 in addition to post 29 is comprised of a pair of mating peripheral frame elements 30 and 31. Elements 31) and 31 extend laterally with respect to the longitudinal axis of bed and are connected to post 29 to form an overall end wall frame. Frame elements 30 and 31 include a lower generally horizontal portion 32 which is curved or shaped upwardly at its outer extremity into an upwardly extending portion 33. Each portion includes a vertical portion 33a extending from portion 32 terminating approximately half way with regard to the height of frame 14 where it is curved or formed into a second portion 33b which is sloped inwardly back toward post 29. The upper end of portion 33 coincides with the upper limit of support frame 14 wherein it is curved or shaped into an inwardly extending horizontal portion 34 which is directly terminated at post 29 and connected thereto conventionally by a fastener or as shown in FIG. 2, an

offset T-connector 35. In order to keep bed 10 as light as possible, all of the tubing and frame elements are preferably comprised of aluminum or lightweight chrome-plated steel which are easy to keep clean.

The T-connector includes a leg portion 36 adapted to fit onto the upper portion of post 29 with the cross portion 37 offset forwardly from post 29 for receipt of the upper ends of frame elements 30 and 31. The reason for this is to offset the plane defined by frame elements 30 and 31 in front of post 29 to permit the insertion of a one piece end wall 16 (FIG. 1) within the confines of each pair of frame elements 30 and 31. End walls 16 are preferably comprised of a clear-plastic such as polycarbonate and are adapted to be detachably mounted within end frames 26. The detachable feature permits removal of the end walls in the event that external orthopedic equipment must be utilized such as traction equipment which extends from within the confines of support frame 14 externally thereof.

Referring to FIG. 3B, each end panel 16 is symmetrical about its vertical center line and is shown to conform generally to the configuration of frame elements 30 and 31. A pair of cut-out portions 270 and 271 permit the panel to be inserted around plates 21) which will be described in more detail hereinafter. The periphery of panel 16 includes a curved flange 272 comprised of upper portions 274, side portions 276; and bottom portion 278. The curvature of flange 272 matches the radius of the end frame elements so that it nestles about the peripheral end frame elements to prevent the occupant of the bed from getting a grip on the end panels or possibly get his fingers wedged therebetween. A recess 280 extends vertically down the middle of panel 16 and is curved to nestle around end frame post 29. The upper flange portion 274 includes an opening 282 on each side of recess 280 for receiving a pair of keeper plates 38 which depend from upper frame portions 34 to lock the panel to the frame. The cut-out portions 270 and 271 include a keeper tab 284 which is curved outwardly to fit around plates 20 as shown in FIG. 1, 3 and 3A.

To attach the panel to end frame 26, one simply inserts the upper end or the inside of post 29 until keeper plates 38 are inserted into openings 282. The lower portion is then gripped and flexed inwardly until tabs 284 clear plates 20 whereupon the panel is released and the tabs slip in behind plates 20 to secure the panel to the bed without requiring any mechanical fasteners. Recess 280 (FIG. 3B) facilitates the inward flexing of the panel. To remove the panel, the reverse operation is preferred.

As described briefly earlier, support frame 14 is adapted to support platform 19 which in turn supports mattress frame 18 (FIGS. 1 and 2).. Thus, frame 14 essentially forms a shell or enclosure with ends closed by panels 16and sides selectively closed by sides 15 and the bottom closed by platform 19, frame 18 and mattress 17. One important aspect of this invention is the ability to raise or lower the bed as an integral unit relative to base 11. This is accomplished by raising frame 14 unitarily with mattress 17, frame 18 and platform 19 regardless of their Trendelenburg or Gatch positioning.

Referring now to FIG. 5, one form of a lift means 40 for electrically raising and lowering the bed is shown. The lift means to be described herein is provided in both end posts 13 to simultaneously raise both end frames 26 in unison. Since the lift means is identical in both ends, only one will be described in detail. In order to provide lift or descent for support frame 14, an electric motor 41 is mounted to channel frame 21 at approximately its mid point longitudinally with respect to the bed. This is a matter of convenience since motor 41 is utilized to activate both lift means 40 at each end. At the same time, its mid-location tends to shield it from the eye of an observer in those instances where the bed is in a lowered position thereby improving the overall appearance of the bed. Motor 41 includes a drive shaft 42 (FIG. 5) which rotates a worm gear 43 having teeth engaged with a reciprocating worm gear 44 which is driven rotationally about a horizontal longitudinal axis. Worm gear 44 is attached to one end of a rod 45 journaled in a pair of bushings 46 and driven for joint rotation with worm gear 44 by motor 41. Bushings 46 are preferably supports in the form of ductile steel castings. The opposite end 48 of rod 45 includes a right angle bevel gear 50 anchored on a threaded rod 41 extending upwardly through end posts 13 and end frame posts 29. Rod 51 is journaled at its lower end in a bushing 47 comprised of a ductile steel casting similar to bushings 46. Rod 51 is threadably engaged with a ball screw 54 which is connected to post 29 by a pair of pins 56 to provide vertical movement of frame 14 and hence the bed. Ball screw 54 is positioned above the upper end 57 of post 13 which end acts as a lower stop for the bed elevation. In the embodiment shown in FIG. 5, end frame post 29 is approximately twice the height of post 13. Thus, the amount of vertical travel is approximately equal to half of the length of post 29. Preferably the amount of travel is approximately sufficient to raise and lower the overall elevation of the bed surface frame 12-16 inches to 38-42 inches depending on the particular age and size of the patient.

Briefly, rotation of rod 45 through the utilization of right angle bevel gears 49 and 50 causes threaded rod 51 to rotate in the same direction as rod 45 about a vertical axis. The upper end of rod 51 is journaled in a thrust bearing 53, thrust bearing 53 being anchored within end frame post 29 in the vicinity of its upper end. Ball screw 54 is threadably engaged with rod 51 but prevented from rotating relative thereto in a known fashion. Rotation of rod 51 results in axial displacement of ball screw 54 and likewise displacement of post 29. Accordingly, the entire support frame 14 is lifted or lowered evenly at both ends depending on the rotational direction of rods 45 and 51 which is dependent on the directional rotation of motor 41. Thus a simple, dependable and effective lifting means is provided which requires no physical exertion other than the movement of an appropriate switch into the up or down position. A slightly modified form is shown in FIG. 2 which eliminates the utilization of pins 56. In this embodiment the same overall principle is involved utilizing ball screw 540. However an internal tube 55 is threaded to the upper end of ball screw 54a anchored at its upper end to post 29 by a pin 290 receivable in post 29 by an opening 292. A bearing 294 journals tube 55, bearing 294 also being anchored to post 29 by pins 296. Similar to the embodiment shown in FIG. 5, rotation of ball screw 54a transmits vertical movement of end frame 26 through tube 55.

One important objective of this invention as noted earlier is to provide a pediatric bed which is adaptable as a crib, playpen or youth bed. When utilized as a crib, it is desirable to have the bed surface elevated for the sake of the nurse taking care of the infant since the higher the elevation, the less bending required. On the other hand, if the bed is to be utilized as a playpen, it is most desirable that the bed surface be as low to the ground as practical. Finally, when utilized as a youth bed, the elevation of the bed surface ideally lies intermediate that of a playpen and crib. According to this invention, lift means 40 permits raising and lower the bed surface between a minimum elevation from the floor of 12-16 inches and a maximum height of 38-42 inches. After extensive testing, this range of elevation has been found to provide optimum flexibility although wide flexibility is available. The lower elevation permits a child to sit on the mattress with his legs on the floor. The upper limit is desirable for a nurse to service a child without excessive bending etc. The low profile of base 11 is one unique aspect which permits the lowering of bed to a surface elevation of 16 inches.

When bed 10 is utilized as a playpen or crib, sides are preferably in a fully up position. Referring briefly to FIGS. 1 and 24-31, bed 10 includes a pair of identical sides 15 slidably mounted to support frame 14 for independent movement between a fully lowered and fully raised position. The left side in FIG. 1 illustrates the fully raised position while the right side illustrates the fully lowered position. In the preferred embodiment, the sides are also adaptable for positioning in a partially raised position essentially mid-way between the fully lowered and fully raised positions. FIG. 31 illustrates both of the sides positioned at the intermediate position.

With the sides fully raised, the bed is particularly adaptable for use as a crib or playpen. When utilized as a crib, the bed surface is generally raised to its maximum level of elevation as shown in FIG. 25. When utilized as a playpen, the bed is generally lowered to its minimum level of elevation as shown in FIG. 24. The

bed is also adaptable for occupancy by a somewhat older child wherein the encapsulating features required for an infant do not exist. When utilized thusly, it might be preferred to have both sides in their fully lowered positions as shown in FIG. 29. On the other hand, due to the disability or illness of the occupant, there might be some consideration to prevent accidental falling from the bed wherein the sides are positioned in their intermediate positions such as shown in FIG. 31. In any event, no matter what the age or demeanor of the occupant, it is desirable that either side be quickly and easily lowered to permit easy access to the bed.

Since the two sides are identical to each other, only one will be described in particular detail. The particular arrangement of sides 15 is illustrated in more detail in FIGS. 2 and 6-8. Preferably, sides 15 are mounted on a Tambour track (FIG. 2) with the sides being flexible to be folded through a right angle 61 so that when the side is in its lowermost position, it is completely tucked under the bed as illustrated in FIG. 1. In the prior art, the sides generally move vertically in a plane and hence are fully exposed when in their lowermost position. By concealing the sides beneath the bed platform, they are less apt to be damaged, and are more inaccessible to the occupant so that there is less tendency that the occupant will manipulate the sides by himself. In addition, the concealed position is believed to be more appealing in terms of the overall appearance of the bed.

With reference to FIG. 2, a pair of Tambour tracks 58 and 60 are mounted on each end frame 26 and are shaped in conformity with peripheral frame elements 30 and 31. Similar to end frame elements 30 and 31, each Tambour track 58 and 60 includes a lower horizontal portion 62 (FIG. 2) which is smoothly curved into an outer and lower vertical portion 63 which is subsequently smoothly curved inwardly into a sloped portion 64. These portions essentially coincide with portions 32, 33a and 33b described in detail with respect to the shape of peripheral frame elements 30 and 31. However, lower horizontal portions 62 extend the entire width of the bed in order to permit sides 15 to be concealed beneath platform 19 when fully lowered.

Preferably, tracks 58 and 60 are comprised of chromeplated steel or stainless steel having sufficient rigidity so that they need be anchored only at their end points. Referring to FIGS. 2 and 3, vertical portion 63 of track 58 is preferably a little longer than vertical portion 63 of track 60 so that when tracks 58 and 60 are mounted on each end 26, horizontal portion 62 of track 58 is spaced beneath horizontal portion 62 of track 60 so that when both sides are lowered into their lower position, the two sides are stacked relative to each other. To mount tracks 58 and 60 to end frame 26, the lower end of track 58 is mounted to frame element 30 while its upper end is mounted to frame element 31. Conversely, track 60 has its lower end mounted to frame 31 with its upper end mounted to frame 30. With reference to FIG. 3, the lower ends of tracks 58 and 60 are curved slightly upwards to accommodate the full width of sides 15 when lowered into their lowermost position. This may or may not be necessary depending on the overall width of the bed. However in the preferred embodiment, the optimum width of the bed is 32 to 34 inches which is slightly less than the overall height of sides 15. Therefore, to accommodate sides 15 in their concealed positions, the upper and lower edges of sides are slightly exposed. Indeed, in order to provide easy manipulation of the latch assembly 74 to be described in more detail hereinafter, the upper edge of sides 15 are exposed to make the latch mechanism accessible.

A plug-type connector 65 is shown in FIGS. 1-3 for anchoring the tracks to the particular frame element. Connector 65 is cylindrical and includes an annular recess 66 for receipt of the particular end of the track being anchored. It includes a nose portion 67 which inserts into an opening provided in frame elements 30 and 31 to anchor the track to the frame. Nose portion 67 may be threaded into frame elements 30 and 31 with annular openings 66 aligned for the respect of ends of the tracks. As illustrated in the drawings, the upper end of tracks 58 and 60 are anchored just below the tennination point between upper horizontal portion 34 and slope portion 33b of frame elements 30 and 31.

Side 15 itself is preferably comprised of a polyethylene netting 68 which is mesh-like and yieldable. A material such as Vexar is ideal since it is sufficiently stiff to prevent sagging while at the same time flexible enough to move along the shapes of tracks 58 and 60. Another consideration of importance is the occasional abrupt movements by a child causing some portion of the childs body to strike the sides. A polyethylene netting such as Vexar will yield under such contact to minimize the chance of injury occuring. Also, the netting provides excellent anticlimb characteristics because the openings of the netting are too small to penetrate with a childs finger so that he cant get a good grip to climb with. In fact, the Vexar netting has a slick greasylike feel which also makes it difficult to grip. On the other hand it provides good visual penetration in keeping with the total omni vision aspect into and out of the bed.

The sides of the netting are sewn to a flexible piece of extruded piping 69 (FIG. 2) which includes a plural ity of Tambour rings 70 attached thereto which slip over tracks 58 and 60 to guide and hold side 15 within the confines of the tracks. As noted earlier in the BACKGROUND, the sides of hospital cribs and beds are often difficult to lower and tend to jam. The utilization of a Tambour track arrangement provides a very smooth and easy movement for the sides greatly reducing any tendency to jam. By properly selecting the spacing of the rings, the movement and folding of the sides as it is traversed along the track is very similar to a plurality of living hinges so that there is little resistance to folding movement of the sides. The lower margin of sides 15 are likewise secured or sewn to a piece of extruded piping 71 similar in configuration to that utilized for the sides. It has been found that an extruded plastic works extremely well in that its material properties provide sufficient strength and flexibility to conform to the movement of sides 15 along tracks 58 and 60.

The upper margin of side 15 is anchored to a cover tube 72 which includes a latch assembly 74 for releasing side 15 when in their fully raised or intermediate positions. Cover tube 72 is preferably a cylindrical tube and includes a radial portion 73 having a generally U- shaped configuration for fitting over the upper margin of netting 68 for anchoring the same thereto by sewing or other conventional means. Each end of cover tube 72 includes a pair of aligned circular openings 75 (FIG. 6) spaced slightly inwardly from each end in general alignment with Tambour rings 70. The Tambour track 60 is mounted through openings thus securely anchoring the upper margin of the sides to the track. At the mid portions of cover tube 72 are a pair of generally L-shaped slots 76 and 77. The main portion of slots 76 and 77 extend longitudinally with respect to tube 72 while their leg portions 78 extend laterally in the same direction from the inner ends respectively of slots 76 and 77. Slots 76 and 77 permit the manipulation of latch mechanism 74 as will be described in more detail hereinafter.

A pair of latch tubes, left hand tube 79 and right hand tube 80 are telescoped within cover tube 72 and through their combined lengths extend longitudinally between the Tambour tracks mounted on each end of the bed. Tubes 79 and 80 are adapted to be biased outwardly so that their outer ends are urged against tracks 60 in accordance with the operation of the latch mechanism which will now be described. Left hand tube 79 extends beyond the mid portion of the bed and includes at its inner end a reduced portion 81 having an elongated slot 82 open at its inner end. Spaced outwardly from reduced portion 81 is a tap 83 for receipt of a latching pin 84 shown in FIG. 2. Right hand tube 80 is similar in cross section to tube 79 except that it does not include a portion corresponding to reduced portion 81 of tube 79. Rather, tube 80 is adapted at its inner end to receive portion 81 for telescoping movement within its inner end. Spaced inwardly from its inner end is a tap 85 (FIG. 8) adapted to receive latching pin 86 (FIG. 2). In addition to tap 85, right hand tube 80 includes a radial opening 87 spaced inwardly from its inner end a distance approximately equal to the longitudinal extension of reduced portion 81. Opening 87 is adapted to receive a threaded pin 88 (FIG. 6) which extends through the diameter of tube 80. A coil spring 1 89 is inserted concentrically within the inner end of tube 80 against pin 88 for abutment at its opposite end by the inner end of tube 79. In this fashion, when tube 79 is positioned within cover tube 72 along with tube 80 so that portion 81 is telescoped within the inner end of tube 80, spring 89 is compressed between pin 88 and the inner end of tube 79 so that tubes 79 and 80 are biased outwardly. With the tubes inserted so that taps 83 and 85 are exposed beneath slots 76 and 77, latch pins 84 and 86 are threaded respectively into taps 83 and 85 to secure the tubes within cover tube 72. A slightly modified form to that shown in FIGS. 6-8 is shown in FIG. 2 wherein the reduced portion 81 is replaced with a rod 81a which fits within the bore of tube 79 and is anchored thereto by a pin 91. Rod 81 telescopes into tube 80 which includes spring 89' and secured in the bore of tube 80 in the same fashion as described with respect to FIGS. 6-8.

The outer ends of tubes 79 and 80 include a generally U-shaped radially extending keeper slot 90 (shown only on tube 80 in FIG. 8) which has a cross sectional diameter less than that of tracks 58 and 60 so that except in specific instances, the outer ends of tubes 79 and 80 abut against tracks with pins 84 and 86 positioned in their innermost position in slots 76 and '77 opposite to that shown in FIG. 6. However, at two se lected points, tracks 58 and 60 include a reduced crosssectional portion or notch 92 (one of which is shown on track 60 FIGS. 6 and 6A). Slot 90 is designed to fit into notches 92 to lock sides 15 to the tracks at that particular position. Notches 92 are positioned on each track 58 and 60 at the extreme upper end of the tracks and at the intermediate positions between the vertical portion 63 and sloped portion 64 of track 60. Thus, ex cept for these two positions, latch mechanism 74 will always be in what is referred to as a travel position. l.e., the side is free for travel up or down along the tracks. However, when tubes 79 and 80 are moved into alignment with a set of notches, spring 89 urges the tubes outwardly so slots 90 engage notches 92 thus stopping and locking the side at that position.

To prevent locking engagement by keeper slots 90, pins 84 and 86 must be manipulated inwardly to prevent engagement. Thus, to move a side from the lowermost position to the uppermost position, the nurse simply squeezes pins 84 and 86 inwardly and lifts the side up past the intermediate notches until the sides reach the upper limit of the Tambour tracks whereupon the pins are released so that tubes 79 and 80 snap into engagement with notches 92 at the upper end of the tracks. Consequently, to release a side from its up or intermediate position, pins 84 and 86 are simply squeezed together and the side is lowered. If the side is in its lowermost position and it is desired to raise it to the intermediate position, the nurse simply lifts the side up without manipulating pins 84 and 86 until they snap into the intermediate notches 92. if on the other hand the side is in its uppermost position and it is desired to lower it to the intermediate position, the nurse initially manipulates pins 84 and 86 to release mechanism 74 whereupon without further manipulation, the side is simply lowered until tubes 79 and 80 snap into place in intermediate notches 92.

In a particular aspect of this invention, it is desired to provide easy adjusting sides which require but one hand to manipulate. Many times a nurse has one arm occupied in holding equipment or an infant and it is desired to manipulate a side without putting the child or equipment down. This invention provides means for automatically locking latch mechanism 74 in a release or travel position so that the side can be independently gripped and moved without grasping pins 84 and 86. To accomplish this, reference is made to slots 90 which have an overall U-shape configuration. It will be appreciated that if tubes 79 and 80 are rotated so that it is impossible to align slots 90 with tracks 58 and 60, regardless of the elevation of the side, it cannot engage either of the intermediate or upper position notches. To accomplish this, the nurse with one hand simply squeezes pins 84 and 86 together and when they reach their innermost positions rotates them upwardly into the leg portions of slots 82. Once rotated into this position, the bias of spring 89 maintains the pins in the leg portion of the slots and the sides are now free to travel entirely from the lowermost position to the uppermost position without snapping into the intermediate notches. Likewise, it can travel from the uppermost position to the lowermost position without snapping into the intermediate notches. A slight modification is shown in FIG. 2 wherein the width of slots 76a and 77a sufficiently exceed the diameter of pins 84 and 86 permitting sufficient rotation of tubes 79 and 80 to lock them in their travel position.

In the embodiment shown, the overall length of tubes 79 and 80 are selected so that when the latch mechanism is in its travel position, there is sufficient engagement between the outer ends of tubes 79 and 80 with tracks 58 and 60 so that the sides are frictionally held in any particular position. That is, when the sides are released or let go of by the user, they will not automatically fall by their gravitational weight. Instead, they require positive motivation to raise or lower the sides. This is particularly useful when the lock means is utilized since it permits the nurse or orderly to manipulate pins 84 and 86 into the lock open position whereupon the same hand can be removed from the side for more firmly gripping it to raise or lower it without worrying about it dropping suddenly down.

An important safety feature provided by this invention is the inaccessability'to the occupant to latching pins 84 and 86 for manipulation of the latch. Cover tube 72 and latch tubes 79 and 80 are arranged so that pins 84 and 86 extend vertically downwards on the outside of netting 68. By simply locating the latch mechanism on the outside of the sides, they are difficult to get at by the child. To begin with, the Vexar netting prevents penetration by the childs fingers for manipulation from within the crib. Therefore, it is necessary that the child reach up over the top of the side and then downwards to handle the latches. The vertical downward orientation simply makes it more difficult should the child be able to reach over the top of the side. When latch mechanism 74 is locked into the travel position, pins 84 and 86 extend horizontally outwards which places them in slightly closer proximity to the child, however, this position is envisioned as being used only when an attendant is near.

Previously, it has been emphasized that one preferred aspect of sides 15 is its anti-climb characteristic which discourages younger infants from climbing out of the bed when it is utilized as a playpen or crib. The utilization of a polyethylene netting such as Vexar contributes to this in that it cannot be penetrated by an infant's fingers and it is also slippery to the touch thereby making it difficult to get a firm grip on the netting. An additional and important anti-climb characteristic is provided by the inwardly sloped upper portion 64 of tracks 58 and 60 which guides sides 15 into a likewise inwardly sloped configuration when the sides are locked in their uppermost position. This inwardly sloped portion greatly reduces the opportunity for a young infant to climb out of the crib thereby reducing the possibility for injury resulting from a fall. Should the child be capable of gripping some portion to lift himself up onto the side, its inward slope makes it much more difficult to traverse.

Having described the Tambour sides in detail, it should be obvious how to raise and lower a particular side independently of the other into a fully lowered, intermediate or fully raised position. As illustrated in FIGS. 1 and 29, when the sides are lowered into their fully lowered position, they are essentially concealed and positioned under the bed platform 19 and hence protected from undue wear and tear which is always present when children are around. Referring now back to H6. 1, mattress 17 is shown mounted on platform 19 which is secured to support frame 14. The mattress and platform are shown in one of several Trendelenburg positions. Briefly, Trendelenburg positioning refers to the angle at which the patient lies with respect to the horizontal. This ranges from 0 to a plus or minus angle. l.e., the head can be raised with respect to the feet or lowered with respect thereto. Since the concept of Trendelenburg positioning is well known, only the details of the structure permitting this positioning will be described herein.

Mattress support platform 19 is preferably comprised of a generally rectangular frame member having a pair of sides 95 and ends 96 interconnected or formed as a unitary member. To conserve material and reduce the overall weight as much as possible, sides 95 and ends 96 preferably comprise aluminum channel elements which provide sufficient rigidity and strength for support of the occupant. In addition to platform 19, an additional mattress frame 18 is connected to platform 19 and adjustable for Gatch positioning. The mattress is secured to frame 18 which in turn is connected to platform 19. Each side 95 of platform 19 includes one or more longitudinally spaced and aligned openings 97 for mounting frame 18 thereto.

In keeping with the principal objectives of this invention the utility of this bed is enhanced by providing means for Trendelenburg positioning. On the other hand, since cost is not an insignificant factor, the preferred embodiment utilizes manual adjustment although mechanized adjustment could be provided. Referring to FIG. 10, an arm 97 is secured to each end of sides 95. The arms extend from the lower surface to permit mattress 17 to fit over platform 19 as will be described hereinafter. Each arm extends outwardly at an angle from sides 95 and then longitudinally outward parallel thereto. A generally U-shaped handle bar 98 is connected at each end to a pair of arms 97 to form a lift handle similar in part to a stretcher. Handles 98 include a mid portion 99 extending parallel to ends 96 of the platform and exceed the width of the platform. Each end of handle 98 is turned inwardly at right angles to mid portion 99 for connection to the longitudinal extending end portions of arms 97. They are connected to arms 97 by a connector 100 which also acts as a guide to permit quick and easy Trendelenburg positioning adjustment.

Connector 100 (FIG. 4) has a tubular configuration and includes an outer and inner end portion 101 and 102 separated by a mid portion 103. The support of platform 19, mattress frame 18 and mattress 17 is provided by the association between connectors 100 and Trendelenburg plates 20. Since arms 97 extend essentially from each corner of platform 19, four plates 20 are provided, one for association with each arm and connector. In describing the cooperation of connectors 100 with Trendelenburg plates 20, only one will be critically examined, the remainder of which are identical.

Each end frame 26 includes a Trendelenburg plate 20 affixed to each lower inner corner. Plate 20 is relatively flat to lie in the plane of ends 26. They are vertically elongated and shaped at lower end 106 to nestle within the contour of the termination between lower horizontal portion 32 and lower vertical portion 33a of each frame elements 30 and 31. In the preferred embodiment, plate 20 is welded to the appropriate interior portions of frame elements 30 and 31 and are comprised of aluminum or chrome-plated steel. Each plate includes a vertical elongated slot 107 with an enlarged opening 108 and 109 at each end and an intermediate enlarged opening 110 in between the end openings. Opening 109 has a diameter in excess of the largest cross sectional dimension of connector 100 to permit endwise movement of connector 100 into and through opening 109.In this fashion, platform 19 can be attached to end frames 26 through plates 20 by inserting connectors through openings 109; affixing portion 102 to the outer end of arms 97 of platform 19; and then affixing handle bar 98 to the opposite portion 101 of connector 100 to securely confine platform 19 within the movement of slots 107 of plates 20. Thus, regardless of the platform position in the slot, it along with frame 18 and mattress 17 are positively suspended from frame 14.

Referring to F IG. 4, each end of handle 98 is securely affixed to end 101 of connector 100 in a conventional fashion. The outer end of arms 97 however are secured to connector 100 for sliding engagement relative thereto. In the preferred embodiment, arm 97 telescopes within connector 100 and is a solid bar. An elongated recess 111 is provided in. arm 97 but does not extend to its outer end. A set screw 112 is threadable radially through end portion 102 of connector 100 for extension into slot 111 so that connector 100 and attached handle 98 are slidable endwise relative to arms 97 the length of recess 11 1. The significance of this will be clarified shortly.

Turning now to the cross-sectional configuration of each connector 100 (FIG. 4), each end portion 101 and 102 increases in cross section inwardly from their respective outer ends to a maximum at the juncture with mid portion 103. Mid portion 103 has a cross section which varies as follows. At the juncture with end portion 102, the cross sectional diameter of mid portion 103 decreases rapidly to a minimum at 113 and then slopes upwardly once more toward a maximum at the juncture with end portion 101 at 114. Thus, the overall cross sectional diameter along any point of mid portion 103 is substantially less than the maximums of end portions 101 and 102. The configuration of mid portion 103 is selected such that at its minimum cross sectional point 113, it will slide freely up or down elongated slot 107 of plate 20. However, when it is positioned within one of the openings 108, 109 or 110, endwise movement of handle 98 and connectors 100 inwardly permits movement of the connectors so that the enlarged cross section configuration of mid portion 103 at 114 is aligned with slot 107 and hence prevented from vertical movement relative thereto since it is substantially greater dimensionally. In this fashion, the height of each end of platform 19 is adjusted. With the platform arranged for example as shown in FIG. 1, the nurse or orderly simply pulls outwardly on handle 98 so that connectors 100 and handle 98 move relative to arms 97 until the point 113 is aligned with slot 107. At this time, the end of platform 19 can be raised to either of two positions. The first position is when connector 100 is aligned within opening 110 and the second is when connector 100 is aligned with opening 109. After selecting the desired position, the nurse or orderly sim ply pushes inwardly on handle 98 until portion 11 1 of mid portion 103 is positioned within the desired opening. This locks the connector in the slot since this enlarged cross sectional dimension cannot traverse slot 107. Thus, the connectors on each end of platform 19 are selectively captured within one of openings 108, 109 or 110 to position that end of platform 19 at the desired level. In this fashion, the Trendelenburg positioning of the platform is selected from the head up to the head down or level position. it will also be appreci ated that the cooperation of plates 20 and connectors 100 do provide some height adjustment for the platform independent of lift mechanism 40 described hereinbefore. Although only three openings are shown in plates 20, more could be utilized although three have proven to provide adequate Trendenenburg positioning.

An alternative configuration for mid portion 103 of connector 100 is a non-linear portion (not shown) which cams portions 1 14 into one of the selected openings thus necessitating affirmative movement of each connector from the slot to alter its position.

Referring now to FIGS. 10-13 mattress frame 18 will be described in detail. The primary function of frame 18 is to provide for Gatch position adjustment. Gatch positioning is well known in the art and refers to the knees-up, back-up arrangements for a patient reclining in a bed. Again, within the objectives of this invention, manual Gatch positioning is provided in order to keep the overall costs within an acceptable range. However, it will be appreciated that mechanized Gatch positioning could be utilized.

Frame 18 is essentially comprised of a pair of subframe assemblies 116 and 117 each of which is pivotally connected to platform 19. Sub-frame 116 (FIG. 10) provides the adjustable back support for the patient and is adjustable from the horizontal position to a plurality of incline positions for raising the patients back and head. Sub-frame 117 supports the patients legs between a horizontal and inclined knees-up position.

Frame 116 includes a pair of generally U-shaped telescoping frames 118 and 119 with the legs 120 of frame 118 forming a telescoping fit within the legs 121 of frame 119. Legs 121 are preferably tubular box-shaped channel members so that when legs 120 are inserted therein, frame 118 is prevented from rotating relative to frame 119. Legs 120 include a pair of aligned slots 122 through their sides and are concealed within legs 121 when telescoped therein. Legs 121 include a pair of aligned openings 123 through their sides for insertion of adjusting pins 124 which when inserted through openings 123 and slots 122 prevent endwise removal of upper frame 118 from lower frame 119. According to the length of slots 122, the overall length of sub-frame 116 can be adjusted. With frame 118 inserted in frame 119, a rectangular configuration is provided.

The web portion 125, of frame 119 is preferably a hollow tubular element having an overall length sufficient to fit snugly between the inner walls of sides 95 of platform 19. It is aligned with one of the pairs of openings 99 provided through sides 95 for insertion of a fastening element 126 on each side which fits through opening 99 into each end of web portion 125 for threaded engagement therewith which when tightened locks sub-frame 116 in its desired angular position relative to platform 19. Thus, to raise back support frame 1 16 relative to platform 19, the nurse or orderly simply loosens elements '126 on each side of the sub-frame and raises the frame to its desired angle of elevation whereupon elements 126 are tightened to secure the subframe in its desired position. A handle 127 is preferably attached near the outer end of each leg 120 of frame 118 to facilitate the lifting and lowering of sub-frame 116 into its desired position. The back support frame 116 is thus rotatable independently of the knee support adjustment frame 117. Preferably fasteners 126 always maintain sufficient frictional engagement with web 125 to prevent abrupt downward movement of back support 116 when it is lowered.

Referring now to the knee support sub-frame 117, it is also comprised of a pair of frames 130 and 131 which are interconnected. Frame 131 is similar to frame 121 described with respect to the back support frame in that it is generally U-shaped including a web portion 132 and two legs 133. Frame 130 is comprised of a generally H-shaped frame (FIG. 11) having a pair of lower leg portions 134 and upper leg portions 138. Legs 134 are adapted dimensionally to fit snugly outside legs 133 of frame 131. They include a longitudinally extending recess or keeper slot 136 (FIGS. 10 and 12) adapted for receipt of a longitudinally extending keeper 137 extending laterally from the outer sides of legs 133 so that when these legs are flexed inwardly to permit keepers 137 to project into slots 136, frames 130 and 131 are interconnected so that they will not rotate relative to each other. At the same time, keepers 137 are permitted to slide endwise within slots 136 so that longitudinal adjustment of sub-frame 117 is provided. The upper legs 138 of frame 130 slopes downwardly at an angle with respect to lower legs 134 to provide for knee bending when frame 1 17 is raised into a Gatch position. Since frame 18 is sized to fit with sides and ends 96 of frame 19, legs 138 project downwardly from mat]- ress 17 when lowered to permit a horizontal bed surface. The upper and lower leg of frame are rigidly interconnected by cross support 135. According to the preferred embodiment, the knees of the patient should be located approximately above cross bar 135 which is where legs 138 slope downwardly. Since children vary greatly in size and growth rates, lengthwise adjustment of the positions of cross bar 135 is essential. In fact, the length-wise growth rate of the thighs tends to exceed that of other bone structures in children. Thus, some adjustment is necessary in order that this type of bed accommodate various sized children. The cooperation of keepers 137 and slots 136 provide a sufficient range of adjustment in the overall length of knee adjustment support frame 117. Thus, it is possible in accordance with this invention to locate the juncture point between upper and lower legs 134 and 138 beneath the patients knees simply by extending or retracting the upper frame 130 relative to frame 131.

The Gatch position is achieved by pivotally mounting sub-frame 117 relative to platform 19 in a fashion similar to back Support adjustment sub-frame 1 18. The web portion 132 of frame 131 is preferably tubular and extends dimensionally to fit snugly within sides 95 of platform 19. When aligned with one of the pairs of openings 99 provided in sides 95 of frame 19, appropriate fasteners (not shown) are inserted through openings 99 to pivotally secure sub-frame 117 to platform 19.

A support brace 140 is swingably mounted to frame 117 to lock sub-frame 117 into the Gatch (knee-up) position. Brace 140 includes a horizontal portion 141 and a pair of upwardly extending finger-like projections 142 bent outwardly at their upper ends to form a horizontal pin portion 143. Pins 143 are adapted to fit within an opening 144 provided at the outer end of leg 133 of frame element 131, pins 143 being of sufficient length to fit through openings 144 and extend into slots 136 of frame element 130. Once installed, brace 140 is swingable from the vertical configuration shown in FIGS. 10-13 to a horizontal configuration. In the horizontal position, brace 140 is sandwiched between platform 19 and frame 130. In its vertical orientation as shown in the drawings, the leg support frame 117 is raised into the Gatch position. A keeper plate 145 having an indent 286 is mounted on each inner face of sides 95 of platform 19 to anchor sub-frame 117 into the Gatch position. Plate 145 includes a vertical portion 287 having a sloped upper edge which dams the ends of horizontal brace portion 141 into and out of indent 286 when sub-frame 117 is lifted into or out of the Gatch position.

As a result of the foregoing, the manipulation of Gatch frame 18 should be obvious. In order to raise back support frame 116 into a desired angular position with relation to platform 19, fasteners 126 are loosened to permit free rotation of frame 18 by gripping handle 127. When the desired position is reached, elements 126 are tightened to secure the back rest in the desired position. In order to raise the knee support frame 117 into the Gatch position, frame 117 is lifted up to permit brace 141 to swing downwardly into a vertical position until brace 141 is captured in recess 286 of keeper 145. It will be appreciated that appropriate dampers can be utilized in connection with the rotation of knee support frame 117 so that the movement is not abrupt. In order to adjust the overall length of knee support frame 117, upper portion 130 can be moved endwise relative to lower portion 131 by the inter-engagement of keepers 137 in slots 136.

Referring now to FIGS. 1 and 9, the latter figure illustrates mattress 17 in perspective at a significantly reduced scale. F IG. 1 shows the mattress installed on the finished product with a sheet 141 completely covering the mattress. Mattress 17 is designed to completely shield frame 18 except for the protrusion of handles 127. Ideally, mattress 17 should be thin relative to its length and width to facilitate bending without significantly wrinkling sheet 141 as frame 18 is manipulated into one or more Gatch positions. In the preferred embodiment, the mattress is molded from ABS plastic and includes a foam overlay of urethane. This provides a mattress material which is not only durable, but extremely light to handle and extremely flexible to permit folding movement into various Gatch positions. In addition, it is not condusive to soiling and in any event is easy to clean. The particular details of mattress 17 are shown clearly in FIGS. 14-23.

The basic cross sectional configuration of mattress 17 is shown in FIG. 15. The underside 142 is a molded or extruded plastic having depending rib and channel portions to provide sufficient strength and utility, the details of which will be described hereinafter. The entire upper margin 143 of underside 142 is continuous and smooth so that an upper layer 144 of polyurethane foam can be attached thereto. This upper layer of foam provides the essential body support for the mattress while the underside 143 is functional to receive frames 18 and 19 as well as provide the requisite bending and strength for the mattress.

Referring to FIG. 14, underside 142 includes three central longitudinally spaced portions 145, 146 and 147 which provide the central strength and support respectively for the legs, thighs and back of the patient. A spacing 157 is provided intermediate portions 145 and 146, (FIGS. 14 and in which are disposed two laterally extending box-like ribs 148 and 149 spaced equally from each other and the adjacent central portions 145 and 146. This provides three identical channel-ways 150, 151 and 152 extending laterally across the width of mattress 17. Each channel-way includes a pair of side walls 153 and a ceiling 154 dimensional to receive cross support (FIG. 1 1) of Gatch frame 18 which is the point of bend for the knees of the patient. As noted earlier, the overall length of the knee support subframe 117 is adjustable to accommodate children or infants having thighs of varying lengths. The provisions of channel-ways 150, 151 and 152 permits three selected adjustments which has proven adequate within the range of patients for which the bed is designed. The width and depth of the channel-ways is selected to provide a snug friction fit over cross bar 135. The ceiling 154 of each channel-way includes a pair of indents 155 extending laterally across the ceiling to form what is known as a living hinge. This living hinge permits continuous bending of the mattress at this point while re ducing any tendence to tear or fatigue.

Intermediate central support portions 146 and 147, there is a spacing 156 substantially wider than channelways 150, 151 or 152. This spacing defines the juncture and bending point between the back rest sub-frame 116 and the knee support sub-frame 117 (FIG. 11)). In addition, the angular rotation of the back rest support .is substantially greater than the knee support. As shown in FIG. 15, the normal range of bending the back rest support is between zero and 90. In order to facilitate bending, a pair of laterally extending indents 1550 are provided laterally along spacing 156 identical to the indents located at spacing 57 to form a living hinge. Spac ing 156 is also utilized to accommodate web portions 125 and 132 which form the pivotal axis for sub-frame assemblies 116 and 117.

A plurality of inverted cup-shaped openings 1611 are randomly provided in each of the central portions 145, 146 and 147 in order to economize the amount of material required without reducing its; overall strength and support. These spaced recesses 180 also tend to provide a more comfortable mattress since it yields proportionately better than a solid mass. Referring to FIG. 15, ribs 148 and 149 are also preferably hollow and tubular in configuration to reduce the overall amount of material required as well as enhance its function as a mattress.

Referring now to FIGS. 14 and 16, a pair of generally continuous grooves 158 and 162 .are spaced inwardly with respect to each other and from the outer periphery of mattress 17. The outer groove 158 is formed by a pair of downwardly depending flanges 159 and 160 (FIG. 23) forming a pair of side walls 161. Groove 158 is continuous except for its interruption at the spacings 156 and 157 between central portions 145, 146 and 146, 147 which spacings extend laterally the entire width of mattress 17. Consequently, groove 158 is comprised of two generally U-shaped end portions and an intermediate straight portion on each side extending the length of central portion 146. Where this type of mattress is utilized with a rigid frame, the groove could be continuous.

Disposed within each portion of groove 158 is a sheet retaining extrusion 164. Extrusion 164 is preferably tubular and has a box cross section so that it can be snugly disposed within groove 158 intermediate side walls 161. The lower ends 165 of extrusion 164 are formed inwardly and upwardly into contact with each other at their innermost ends 166 to form a pair of gripping fingers 167 resiliently biased into contact with each other to grip the peripheral edging 168 of sheet 141. This provides a very simple and convenient sheet gripping element extending substantially continuously around the periphery of mattress 17. The nurse or orderly simply places the sheet over the top side of mattress 17 and wedges the peripheral edges 168 of the sheet in between fingers 167. Preferably, fingers 167 are flexible enough to permit a persons fingers to be wedged therebetween while at the same time they are of sufficient resiliency to return to their normal abutting position to grip the sheet therebetween after ones fingers are removed. In this fashion, the sheet can be quickly removed from extrusion 164.

Extrusion 164 provides two significant advantages. It eliminates the somewhat clumsy and ineffective traditional way of anchoring a sheet to a mattress which is to simply fold the overflap beneath the mattress. This type of tucking can quickly become ruffled. In addition, it permits the utilization of a sheet of smaller size in relation to a given mattress size since the edging need extend over the mattress only a distance to anchor it within fingers 167. Therefore, sheet gripping extrusion 164 provides economical savings in relation to the size of sheet required in addition to making the overall job of changing sheets much simpler. Although other materials are envisioned, in the preferred embodiment, extrusion 164 is comprised of an extruded plastic tubmg.

Groove 162 is spaced inwardly from groove 158 by flange 160, the inner portion 169 of which forms the outer boundary of groove 162. The triangular configuration of flanges 159 and 160 shown in FIG. 23 are to provide sufficient strength in side walls 161 to provide a quasi-wedge engagement between the side walls and extrusion 164. The utilization of groove 162 does not necessitate a wedge engagement and therefore a vertical side wall is not required. The innermost side of groove 162 is formed by the outer walls of central portions 145, 146 and 147. Groove 162 similar to groove 158 is interrupted at the spacings between the central portions and hence is essentially comprised of two generally U-shaped end portions and a pair of intermediate straight portions extending essentially the length of central portion 146. Groove 162 is substantially wider than groove 158 and is designed to accommodate the placement of mattress 17 over platform 19 and frame 18. The depth of groove 162 is essentially equal to the height of sides 95 and ends 96 of platform 18 which are disposed in groove 162 along its outer portion. It is less than the depth of groove 158, the significance of which will be clarified shortly. Since sub-frames 116 and 117 of frame 18 fit within the confines of platform sides 95, they are disposed in the innermost portion of groove 162. In this fashion, central portion 147 is disposed within the sides and web portions of frames 118 and 119 (FIG. central portion 146 is disposed intermediate the sides and web portions of frames 130 and 131 while central portion 145 is disposed within upper legs 158 and cross support 135 of frame 130. It will be appreciated that as frame 18 is manipulated to raise the knees and back, portions of mattress 17 are lifted off and away from support platform 19. However, when frame 18 is in the overall horizontal position, mattress 17 encloses and shields both the mattress frame 18 and support frame 19.

The overall length of frame 18 is such that the ends of legs 138 (FIGS. 10-13) do not extend over end 96 of support frame 19. Thus, when frame 18 is in its generally horizontal position, legs 138 which are angularly related to the remainder of frame 18 extend downwardly away from platform 19 permitting mattress 17 to lie completely in a horizontal plane.

Referring now to FIGS. 16 and 17, a recess 175 (FIG. 16) is provided to accommodate handles 127 (FIG. 10) which are attached to the upper surface of frame 118. As mentioned earlier, handles 127 extend laterally to each side of the back support adjust frame 116 and since the sides of this frame lie within sides of platform 19, the handles are attached to the upper surface and project over the upper surface of sides 95. The handle recesses 175 are positioned in the upper surface of groove 162 which is one reason that groove 162 is less in depth than groove 158. This is best illustrated in FIG. 17 which is a cross sectional view of mattress 17 taken along line 1717 of FIG. 16.

FIGS. 17-22 represent various cross sectional views of underside 142 of mattress 17 and illustrate in detail the particular preferred configuration. As noted earlier, one primary objective is to provide a mattress having a low profile without sacrificing durability and comfort. FIGS. 17-22 ilustrate a configuration for a mattress molded from ABS plastic which achieves these objectives. In the preferred embodiment, mattress 17 has a combined thickness of 2 inches. Preferably, the thickness should not exceed 3 inches or it becomes cumbersome to manipulate In addition, mattress 17 is anchored to frame 19 to prevent it from sliding down as it is folded.

Having described one particular form of my invention in detail, its operation should be obvious. Briefly, the height of the bed surface (FIG. 1) from the floor is adjustable between what has been found to be an optimum range of 12-14 inches at its lowest elevation to the highest elevation of approximately 42 inches. The lower elevation is not only ideal when the bed is utilized as a playpen, but with the sides lowered, it permits a child to sit up naturally in bed with his legs extended over the side in contact with the floor. Selection of a particular height is achieved simply by operating a three-way switch to the up or down position so that bidirectional motor 41 through worm gear 43 rotates rod 45 which cooperates with vertical rod 51 and end post 13 through a pair of right angle beveled gears 49 and 50. Rotation of rod 51 provides axial displacement upwards or downwards of worm gear 54 which is anchored to end frame post 29 to raise or lower support frame 14 which includes mattress 17, mattress frame 18 and platform 19. Each end post 13 includes a lift mechanism 40 so that motor 41 simultaneously acts on both end frames of the bed.

A particular Trendelenburg position is achieved by simply pulling out on handle bar 98 (FIG. 10) so that the two connectors attached thereto are positioned with mid portion 103 aligned in slot 107 (FIGS. 3 and 4). At this position, connector and hence platform 19 is free to move vertically in slot 107 into the upper, middle or lower position wherein connector 100 is aligned with one of the openings 108, 109 or 110. Having selected the desired position, the opposite force is exerted on handle bar 98 by pushing it inwardly until the larger cross sectional portion 114 of mid portion 103 is positioned in one of openings 108, 109 or 110 thus preventing further vertical movement in slot 107. The unique arrangement of plates 20 and connectors 100 provide positive and reverse Trendelenburg positioning as well as a means separate from lift mechanism 

1. A mattress comprising resilient gripping means for positively removably anchoring the peripheral edges of a sheet to the mattress so that the sheet encloses the upper surface and sides of said mattress in essentially wrinkle-free fashion.
 2. The mattress according to claim 1 wherein said gripping means is comprised of one or more gripping means positioned around the periphery of said mattress on its underside.
 3. The mattress according to claim 2 wherein said mattress includes a generally continuous groove opening downward from said underside, said gripping means includes one or more channel members corresponding dimensionally to said groove to fit snugly therein, said channel member including a pair of resilient finger-like projections extending inwardly from the sides of said channel member and longitudinally the length of said channel members in abutment with each other to releasably grip the edges of a sheet.
 4. The mattress according to claim 3 wherein said channel members are tubular and formed of extruded plastic, said fingers projecting inwardly from the lower ends of said channel member and being flush with the underside of said mattress.
 5. The mattress according to claim 4 wherein said plastic extrusion is continuous around the periphery of said mattress.
 6. The mattress according to claim 3 wherein said mattress is comprised of an upper and lower leg support portion and a back support portion, first and second hinge means interconnecting said upper and lower leg portions and said upper leg portion and back support portion so that said portions are free for joint and relative rotation to each other.
 7. The mattress according to claim 6 wherein said mattress includes an upper cushion portion and a lower support portion affixed to said cushion portion, said lower portion comprised of plastic and including a reduced cross-sectional portion extending laterally the width of said mattress at each of said first and second hinge means, said reduced cross-sectional portion including one or more living hinges to permit rotation of one or more of said portions relative to the other.
 8. The improvement according to claim 4 wherein said second groove is interrupted at each of said reduced cross-sectional portions, said channel means likewise being interrupted across said reduced cross-sectional portion means to permit said mattress to be mounted over a mattress support frame having cross bars positioned at said reduced cross section portions. 